Workaround issues with "" overloading on some perls

I think that perl 5.16.3 had the issue. Have to check again if
release 0.90 was in fact broken (colors not evaluated into term strings
but instad expanded as "AngelPS1::Color=SCALAR(0x...)").
Bump $VERSION to 0.91
t/50-DateTime.t: fix syntax error
Add a first testcase for AngelPS1::Chrome
Release v0.91